1. Field of the Invention
This invention relates to a transmission electron microscope and a three-dimensional observing method.
2. Description of the Prior Art
Conventionally, a CT method or a stereographic projection method were available as a three-dimensional observing method using a transmission electron microscope (TEM). With the CT method, the projection images of a given portion of a sample are photographed within a predetermined range of observation angle while the sample is rotated by 0 degree to 180 degrees, and processed in image to obtain a three-dimensional structure of the portion of the sample as a three-dimensional observation. With the stereographic projection method, two images of a sample are photographed at different angles by a parallactic angle while the sample is rotated, and observed three-dimensionally by means of stereo viewer after development and exposure.
With the CT method, however, it takes long time to perform the image processing, so that the change of the sample can not be observed in real-time. With the stereographic method, the development and exposure of the images are required in addition to the rotation of the sample, so that it takes several ten minutes to perform the entire process and the change of the sample can not be also observed in real-time.